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If an electron has a wavelength, does it also have a colour?
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Planck's constant has the same dimensions as
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Two photons of
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Let nr and nb be the number of photons emitted by a red bulb and a blue bulb, respectively, of equal power in a given time.
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A bulb rated 60 W at 220 V is connected across a household supply of alternating voltage of 220 V. Calculate the maximum instantaneous current through the filament.
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The equation E = pc is valid
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The work function of a metal is hv0. Light of frequency v falls on this metal. Photoelectric effect will take place only if
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Light of wavelength λ falls on a metal with work-function hc/λ0. Photoelectric effect will take place only if
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When stopping potential is applied in an experiment on photoelectric effect, no photoelectric is observed. This means that
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If the frequency of light in a photoelectric experiment is doubled, the stopping potential will ______.
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A point source of light is used in a photoelectric effect. If the source is removed farther from the emitting metal, the stopping potential
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A point source causes photoelectric effect from a small metal plate. Which of the following curves may represent the saturation photocurrent as a function of the distance between the source and the metal?
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When the intensity of a light source in increased,
(a) the number of photons emitted by the source in unit time increases
(b) the total energy of the photons emitted per unit time increases
(c) more energetic photons are emitted
(d) faster photons are emitted
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Photoelectric effect supports quantum nature of light because
(a) there is a minimum frequency below which no photoelectrons are emitted
(b) the maximum kinetic energy of photoelectrons depends only on the frequency of light and not on its intensity
(c) even when the metal surface is faintly illuminated the photoelectrons leave the surface immediately
(d) electric charge of the photoelectrons is quantised
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The dielectric strength of air is 3.0 × 106 V/m. A parallel-plate air-capacitor has area 20 cm2 and plate separation 0.10 mm. Find the maximum rms voltage of an AC source that can be safely connected to this capacitor.
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A photon of energy hv is absorbed by a free electron of a metal with work-function hv − φ.
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If the wavelength of light in an experiment on photoelectric effect is doubled,
(a) photoelectric emission will not take place
(b) photoelectric emission may or may not take place
(c) the stopping potential will increase
(d) the stopping potential will decrease
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The collector plate in an experiment on photoelectric effect is kept vertically above the emitter plate. A light source is put on and a saturation photocurrent is recorded. An electric field is switched on that has a vertically downward direction.
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In which of the following situations, the heavier of the two particles has smaller de Broglie wavelength? The two particles
(a) move with the same speed
(b) move with the same linear momentum
(c) move with the same kinetic energy
(d) have fallen through the same height
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Calculate the momentum of a photon of light of wavelength 500 nm.
(Use h = 6.63 × 10-34J-s = 4.14 × 10-15 eV-s, c = 3 × 108 m/s and me = 9.1 × 10-31kg)
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